A deflectable catheter assembly is disclosed. The assembly comprises a catheter shaft having a catheter proximal section and a catheter distal section, and at least one lumen extending therethrough. The catheter distal section is more flexible than the catheter proximal section. A tendon is disposed within a first lumen of said catheter shaft. The first lumen is approximately centrally located within the catheter shaft at the catheter proximal section. The first lumen is located off-center of the catheter shaft at the catheter distal section. The tendon is able to deflect the catheter distal section when being pulled on. A catheter handle is coupled to the catheter shaft at the catheter proximal section, the catheter handle includes a control mechanism to control the tendon.
